Well pumping system with gas separator



C. J. COBERLY WELL PUMPING SYSTEM WITH GAS SEPARATOR April 6, 1954 2 Sheets-Sheet l Filed NOV. 25, 1949 WMV April 1954 C. J. COBERLY WELL PUMPING SYSTEM WITH GAS SEPARATOR Filed Nov. 25, 1949 2 Sheets-Sheet 2 Z/'vg/E/vrop: 62 APE/V65 d 0055? Patented Apr. 6, 1954 f UNITED STATES PATENT OFFICE WELL PUMPING SYSTEM WITH GAS SEPARATOR Clarence J. Coberly, Los Angeles, Calif., assignor, by mesne assignments, to Dresser Equipment Company, Cleveland, Ohio, a corporation of Ohio Application November 25, 1949, Serial No. 129,375

19 Claims. (Cl. 10S-46) No. 2,179,481, granted November 14, 1939 andv entitled Pump Inlet Means.

Although my invention is susceptible of other applications, it is of particular utility in the oil industry and will be described in connection with a Well pump for pumping oil and other fluids from an oil well for purposes of illustration. As a matter of convenience, the invention will be considered in connection With a fluid-operated Well pump of the so-called free type, i. e., of the type which is movable hydraulically through a tubing set in the Well between the surface and an operating position in the well, although it Will be understood that the invention is susceptible of application to other types of well pumps.

As is Well known in the art, the Well uid to be pumped from an oil well frequently includes substantial quantities of gas, the latter either being mixed With the liquid components of the well fluid, or being in solution therein. The amount of gas in solution under equilibrium conditions depends on the amount of gas present in the oil producing formation surrounding the well and on the temperature and pressure conditions obtaining in the well. Also, it is possible for well fluid to be supersaturated with gas, i. e.,

to have more gas in solution therein than would normally be the case for a given set of conditions. If the pressure on the Well uid is decreased, as by drawing the well fluid into the pump cylinder of the well pump, or if the temperature of the well fluid is increased, or if the Well fluid is agitated, large quantities of the gas are frequently liberated and separate from the oil to form a foam or froth. As is well known in the art, such free gas has a number of detrimental effects on the pumping system, one of these being that it reduces materially the volumetric efficiency of the well pump. the free gas, being highly compressible, tends to cause the pump to race with the attendant possibility of damage to the pump and other comn ponents of the pump system. My aforementioned prior patent discloses a gas-liquid separator for removing at least a portion of the gas from the liquid components of the well iiuid and a primary object of the present invention is to Another detrimental effect is that provide a gas-liquid separator which incorporates n In my aforementioned prior patent is disclosed an apparatus for delivering well fluid to the inlet of a Well pump which includes a reservoir, passage means for connecting the reservoir to the Wellin fluid communication therewith so as to convey Well fluid from the Well to the reservoir, Valve means for regulating the flow of Well fluid through the passage means and pressure re' sponsive means for actuting the valve means in a manner to maintain the liquid level in the reservoir below the discharge or outlet end of the passage means so that the Well fluid entering the reservoir by way of the passage means discharges into gas. By maintaining the pressure of the gas in the reservoir above the liquid level therein at, or only slightly above, atmospheric pressure, the pressure of the Well iiuid flowing through the passage means is suddenly decreased as it discharges into the gas in the reservoir so that any gas mixed with or in solution in the liquid components of the well fluid is liberated in the reservoir and is thus separated from the liquid components of the well fluid.

The Well pump is supplied with liquid from the l reservoir, which liquid contains a substantially reduced quantity of gas.

An important object of the present invention is to provide a pump inlet apparatus of the fore- Y going character wherein the valve means controlling the flow of Well fluid from the well into the reservoir is made a part of a standing valve assembly employed in connection with a free, duid-operated pump so that it may be pulled with the standing valve assembly when repairs or :adjustments are necessary. n Another object is to provide a pump inlet apis protected against damage when it is subjected Y to high pressures, which may be the case if the pump inlet apparatus is installed in a Well filled With liquid to a point materially above the point at which the pump inlet apparatus is installed. 'AS will be apparent, if the bellows contained only By para gas at a pressure of, for example, twenty pounds per square inch and were installed in a well four thousand feet below the liquid level in the well, then the volume of the gas inside the bellows would have to be reduced to approximately 1/100 or its original volume in order to balance the higher pressure, which would result in damage to the bellows. On the other hand, if the bellows initially contains a volume of liquid equal to seventy-:live percent of its volume and a volume of gas equal to twenty-five percent of its volume under the same conditions, then the total volume of the bellows would be reduced by only approximately one quarter of its original volume in order to balance the higher pressure. Such relatively slight compression of the bellows will not result in damage thereto, which is an iinportant feature of the invention.

Another object of the invention is to -provide a well pumping system which includes power and production tubings for a` huid-operated pump and wherein the passage means for conveying well fluid from the well into the reservoir comprises a third tubing extending upwardly in the reservoir beside the power and production tubings.

A further object is to provide discharge openings at the upper end of such third tubing which are directed toward and located adjacent a wall of the reservoir so that the Vgas-liquid mixture entering the reservoir through the discharge openings is spread into a relatively thin film over the wall of the reservoir to insure separation of the gas and liquid.

Still another object is to position the discharge openings relative to the wall of the reservoir toward which they are directed in such a manner that the axes of the discharge openings make acute angles with the reservoir wall so that the fluid discharge is approximately tangential to the reservoir wall to enhance spreading over the reservoir wall and to attain essentially a cyclone separator effect.

The foregoing objects and advantages of 'the present invention, together with various other objects and advantages which will become apparent, may be attained through the utilization of the exemplary embodiment of 'the invention which is illustrated in the accompanying drawings and which is described in detail hereinafter. Referring to the drawings:

Fig. 1 is a utility view of a well pumping system, as installed in a well, which incorporates the pump inlet apparatus of the invention;

Fig. 2 is an enlarged, transverse sectional view taken along the broken line 2 2 of Fig. 1;

Fig. 3 is a vertical sectional View taken along the irregular broken line 3 3 of Fig. 2;

Fig. d is a downward continuation of Fig. 3;

Figs. 5, 6 and 7 are transverse sectional views respectively taken along the broken lines 5 5, 6 6 and 1 1 of Figs. land 4.

Referring particularly to Fig. 1, the numeral 9 designates a casing which is set in an oil well, a liner I extending below the lower end of the casing and being'periorated to communicate with an oil producing formation surrounding the well. The casing 9 is provided at its upper end with a casing head i I from which are suspended power andproduction tubings Yi2 and I3, the power and production tubings being connected at their lower ends to a pump inlet apparatus I4 for a well pump i5, which is shown in Fig. 3. In the particular construction illustrated, the well pump I is a fluid-operated free pump which is movable through the power tubing I2 between the surface and an operating position adjacent the lower end of the power tubing, the pump I5 being seated on a pump seat IE carried by the pump inlet apparatus Irl when the pump is in its operating position. As will be discussed in more detail hereinafter, the power tubing I2 is adapted to convey an operating iluid, such as oil, under relatively high pressure downwardly to the fluidoperated pump i5 to operate it and the production tubing I3 is adapted to convey upwardly to the surface fluid discharged by the pump. The fluid-operated free pump I5 may be of any suitable type and will not be considered in detail.

Ingeneral, the pump inlet apparatus I6 includes a housing ,2t which, as best shown in Figs. i and 3, carries a casing packer 2l, the latter engaging 4the -inner wall of the casing 9 to provide above the packer a reservoir 22 from which well iluid is supplied through a passage means 2t to an inlet 2li of the pump I5. As shown in Figs. 1, 3 and 4, the .reservoir 22 is supplied with well iluid from below the packer 2i through a passage means 25, the latter extending upwardly in the reservoir 22 and being provided at its upper end with a discharge means 2E. The pump inlet apparatus 'I4 includes a valve means 2l which regulates the flow of well fluid into the reservoir 22 through the passage means 25 and includes mea-ns -28 .responsive to the pressure of the well fluid in there reservoir for actuating the valve means 2'I to maintain the level of the liquid components of the .well fluid in the reservoir at a point below the discharge means 2t so that the well fluid entering the reservoir through the passage vmeans v25 discharges into gas in the reservoir. As shown in Fig. l, the casing 9 communicates at its upper end with a pipe 29 through .which gas may be drawn off from the casing under the control of a valve 38 to maintain any desired pressure .in the casing and in the reservoir 22, thepressure in the reservoir preferably being maintained at substantially atmospheric pressure for reasons to be discussed hereinafter.

Referring particularly to Fig. 3, the housing 2! of the pump inlet apparatus ill is provided at its upper end with a counterbore .3d into which the lower end of the power tubing I2 is threaded and is provided adjacent the counterbore 34 with a bore 35 into whichthelower end of the production tubing i3 is threaded, the housing being provided with a port 36 which connects the bore 35 to the counterbore 3e so that production uid discharged from an outlet 3l', which may comprise a plurality of ports, of the pump i5 may enter the production tubing i3 to be conveyed upwardly thereby to .the surface. It will be understood that sealing means (not shown) is provided between Vthe pump I5 and ,the power tubing i2 above the outlet 3.? to .separate the operating huid from the production fluid, as is well known in the art.

Communicating with the counter-bore 34 in the housing 20 is a counterbore .38 in which is disposed an annular seat element 3a, the latter being seated on a shoulder 4c formed at the junction of the counterbore 3S with a bore VIH in the housing. Seated on the annular seat element ,39 and disposedin the bore `lll Vis a standing valve assembly 42 which carries the valve means 2l and the pressure responsive means 28, this being an important feature of the invention. The pump seat I6, which 'is tapered to receive a tapered'lower end 43 of the pump I5,

Ysurface of the annular seat element 39.

is formed in a tubular seat element 44 at the upper end of the standing valve assembly 42, the tubular seat element 44 having a tapered external surface which seats on a complementarily tapered The interior of the tubular seat element 44 communicates with the inlet 24 of the pump I5 and has threaded onto its lower end a tube 45 which forms part of the passage means 23 for delivering fluid from the reservoir 22 to the pump inlet 24. As shown in Fig. 4, disposed within the lower end of the tube 45 is a standing Valve 48 comprising a ball check valve 49 which is adapted to seat on an annular seat element 59 to prevent flow through the passage means 25 back into the reservoir 22. The annular seat element 59 is retained by being clamped between the upper end-of a tubular housing I of the valve means 21 and the pressure responsive means 28 and a shoulder 52 in the tube 45. Upward movement of the ball check valve 49 is limited by a cage 53 which is disposed in the tube 45 above the annular seat element 59. The cage 53 is also a permanent magnet which holds the ball check' valve 49 oif its seat when the pump is in operation, the valve 49 seating only when the pump is stopped so that a back flow of fluid occurs to pull the valve away from the magnet and seat it. Thereafter, the ball check valve l49 is held seated by liuid pressure until such time as the iluid pressure thereabove is again reduced by the pump.

As shown in Fig. 4, the bore 4I in the housing 29 communicates at its lower end with a counterbore 58 therein in which is pressed or otherwise secured, a liner 59, the tubular housing 5| carrying three annular sealing elements, such as O- rings 69, 6I and 62 which make fluid-tight seals between the tubular housing 5| and the liner 59. The external diameter of the tubular housing 5| is reduced between the sealing elements 60 and 6I and between the sealing elements 6I and 62 to provide annular spaces 63 and 64, respectively. The annular space 63 forms part of the passage means 25 for conveying fluid from the reservoir 22 to the pump inlet 24 and communicates with the interior of the tubular housing 5| through one or more ports 65 adjacent the sealing element 69 and one or more ports 66 adjacent the sealing element 6|. Fluid may flow from the interior of the tubular housing 5| between arms 61 of an element 68 of the pressure responsive means 28 and through the annular seat element 59 into the tube 45 leading to the pump inlet 24. The annular space 63 communicates adjacent its lower end through ports 69 in the liner 59 with an internal annular groove 19 in the housing 29. As shown in Fig. 4 and l as best shown in Fig. 6, the internal annular groove 19 communicates through radial ports 1| in the housing 29 with the reservoir 22. Thus, the passage means 23 for conveying fluid from the reservoir 22 to the inlet 24 of the pump I5 includes the ports 1 I, the internal annular groove 10, the ports 69, the annular space 63, the ports packer 2|, the packer being carried by a tubular shell 11 having a portion which, as best shown in Fig. 4, is threaded onto the lower end of the housing 29 of the pump inlet apparatus I4. This packer arrangement, which is generally similar to that shown in my aforementioned prior patent, is merely illustrative and any suitable type of packer arrangement may be substituted therefor. Threaded into or otherwise connected to the tubular shell'11 is an inlet tubing 18 extending to the bottom of the well and having a perforated lower section 19 through which well fluid from the interior of the liner I9 may enter the interior of the inlet tubing, the latter forming part of the passage means 25. As is conventional, the inlet tubing 18 acts as a gas-lift flow tubing through which the well uid may be lifted substantial distances with relatively low formation pressures.

As shown in Fig. 4, the well fluid flowing through the inlet tubing 18 enters the counterbore 59 at the lower end of the housing 29 and flows upwardly therein through the valve means 21, as will be discussed hereinafter, into an internal annular groove 82 in the housing 29, the latter communicating through a port 83 with a longitudinal passage 84 in the housing. As shown in Fig. 3, threaded into the upper end of the passage 84 is a third tubing 85 which is positioned side by side with the power and production tubings I2 and I3, which is a feature of the invention. The third tubing 85 extends upwardly a substantial distance in the reservoir 22 and terminates at its upper end in the discharge means 26, the latter comprising an elongated cap 86 which is threaded onto the upper end of the third tubing. The cap 86 is provided with a row of discharge openings 81 therein through which well fluid from the passage means 25 may enter the reservoir. The cap 86 is positioned in close proximity to the casing 9, which forms one wall of the reservoir 22, with the discharge openings 81 therein directed toward the casing so that the well fluid entering the re-servoir is spread over the casing in a thin iilm to promote better gas separation, as will be discussed in more detail hereinafter. Preferably, the axes of the discharge openings 81 are inclined with respect to the casing 9 so that the well fluid discharged therethrough impinges on the casing tangentially to attain some cyclone separator effect and an even film of well fluid over the entire inner surface of the casing between the discharge means 26 and the fluid level in the reservoir 22. In View of the foregoing description, it will be noted that the passage means 25 for conveying well fluid from the well to the reservoir 22 comprises the inlet tubing 18, the counterbore 58 at the lower end of the housing 29, the internal annular groove 82 in the housing 29, the lateral port 83, the longitudinal passage 84, the third tubing 85, the cap 86 and the discharge openings 81 in the cap. The well fluid ows from the counterbore 58 into the internal annular groove 82 in the housing 28 under the control of the valve means 21 by way of ports 99 in the tubular housing 5|, the annular space 84, and ports 9| in the liner 59, the annular space 64 and the ports 99 and 9| also forming part of the passage means 25.

Referring to Fig. 4, the valve means 21 for controlling the iiow of well iluid through the passage means 25 comprises a valve body which includes an upper valve body element disposed in the tubular housing 5|, the upper valve body elementrhaving a shoulder 91 which seats against.`

ashoulder S8 inthe tubular :housing .5| to :limit insertion of the upper valve body element into the tubular housing. Rotation ofthe upper valve body element 96 is prevented by a pin si! carried bythe tubular housing and extending into-a notch it@ inthe upper valve body element.

Seated against the lower end of the upper valve body element 56 is an annular seat element |92 for a valve |53 which is reciprocableinabore IM in a lower valve body `element it, the latter being threaded into the lowerend of the .tubular housing '5| and engaging the annular Yseat element m2 to clamp the annular seat element between the upper end or the lower valve body element |95 and the lower end oi the upper valve body element Qt. The lower valve .body element |l5 is provided with a counterbore I'S therein which provides anannular space around the valve |83, this annular space communicating through ports lill with the counterbore 58 in the lower end of the housing 2B so that well iiuid may enter the counterbore iEiS from the'counterbore 58 through the ports Iill. The well fluid flows from the counter-bore IilB through the annular seat element H22 at a rate determined by the position of the valve |63 relative to the annular seat element, and entersI a counterbore Il in the upper valve body element 95. From the counterbore H0, the well duid nows through ports into an annular space ||2 between the upper valve body element 9G and the tubular housing 5|. The annular space ||2 communi- Cates with the ports 90 in the tubular housing 5| and is sealed at its upper end by an annular sealing element H3 between the upper valve body element 96 and the tubular housing, the annular space H2 being sealed at its lower end by the threaded connection between the tubular housing 5| and the lower valve body element |05.

The valve |33 is provided with a passage therethrough so that the fluid pressures applied to opposite ends thereof are substantially equalized, thereby substantially hydraulically balancing the valve. This is an important feature of the invention since it permits `the pressure responsive means 28 to actuate the valve with the same edectiveness for any formation pressure, i. e., for any pressure of the well fluid flowing through the passage means 25. The valve |03 is provided with a bore I il in its lower end in which is disposed a compression spring H8, the latter being seated at one end on the inner end of the bore yI Il and at its other end on the inner end of the bore Gil in the lower valve body element |05. It will be noted that the compression spring I I9 biases the valve |33 toward its closed position wherein it is seated on the annular seat element |2.

The force applied to the valve |03 by the compression spring ||8 is opposed by the pressure responsive means 2B through a rod H9 which engages the upper end of the valve, the rod II9 being reciprocable in a bore itil through the upper valve body element Ell. The rod H9 is connected at its upper end to a lower head |23 of a bellows |24 having an upper head |25 which is threaded into a bore 25 in the element G8 of the pressure responsive means 28. It will be noted that the compression spring |i8 acts through the valve |03, the rod H9 and the bellows |24 to hold the element e8 seated against the lower face of the annular seat element 5c of the standing valve 48. The bellows IZA. is enclosed by a sleeve |21 having an inturned upper end |28 which is seated on and .may be suitably secured 8 to an external shoulder |29 `on the upper head |25. The lower end of the sleeve |21 is also inturned at Iili to `engage the lower face of the lower head |23, thereby limiting expansion of the bellows |24. The lower head |23 of the bellows .24 is reciprocable in the sleeve |21 and the lower face thereof is exposed to the uid pressure surrounding the bellows, which is substantially the duid pressure obtaining adjacent the lower end of the reservoir 22, so that the bellows is responsive .to the fluid pressure obtaining in the reservoir. As will be apparent, i1" the fluid pressure at the lower end of the reservoir 22 varies from a predetermined value, which corresponds to a predetermined head of the liquid components of the well iiuid in the reservoir, the bellows responds to more the valve |33 relative tothe annular seat element H52 to vary the rate of flow oi well duid through the passage means 25 into the reservoir. As will be apparent, if the level of the liquid components ofthe well Vfluid increases above a .predetermined value, the 'bellows 24 contracts to permit the valve |63 -to move .toward its closed position, thereby decreasing the rate oi flow of well fluid into the reservoir to prevent a further increase in the level therein. The reverse is true when the level falls below the predetermined value. Thus, the bellows |24 serves to maintain the level in the reservoir substantially constant at the predetermined value.

As shown in 4, the bellows |24 is Iadapted to be lled through a passage ISI in the lupper head |25 and a tube |32 which communicates at its upper end with the lower end oi the passage ISI and which extends downwardly into the bellows a predetermined distance, the upper end of the tube 32 being pressedinto a bore in the upper head |25. r'he 4upper end of Athe lpassage |3| serves as a seat for a needle valve |33 which is threaded into a bore in the upper end of the upper head |25 and serves to seal the bellows.

For a reason to be explained in discussing the operation of the present invention, the bellows contains both ya liquid i3d and afgas Ai 35, the volv Lune of lieuid .i3d being at least one-half and preferably three-quarters of the normal volume of the bellows, the remainder or" the normal volurne of the bellows being equal tothe volume of the gas |35 when the exterior of the bellows-is exposed to atmospheric pressure. Itwill be-noted that the tube 32 limits the amount of liquidthat may be introduced into the bellows i2!! so that the proper amount o1" liquid may be introduced readily, which is a feature. lt will be understood that in introducing the liquid into the bellows S24, the bellows cannot be filled with liquid to a level much above the lower end of the tube |32.

Considering the operation of the present irlvention, it will be assumed that the power and production tubings $2 and 3 have been set in the well with the housing 2li connected to the lower ends thereof, the various components of the installation which are rigidly connected to the hou-sing 2D, e. g., the packer 2|, etc., being attached thereto prior to settingthe tubings in the in 'the casing li) :maybe several lthousand vk:test1 bellows.

lows would be compressed to la volume equal to approximately only 1/100 of its initial volume, which would obviously result in damage to the On the other hand, assuming that the bellows |24 is initially lled with seventy-'five percent liquid and twenty-ve percent air under the same conditions and is then run into the well under the same conditions, the bellows is compressed by a factor of only approximately onequarter of its original volume. This is a reasonable amount and will not result in damage. Consequently, my invention provides a pressure reponsive means which may be run into the well without any possibility of ydamage from a high external pressure, which is an important feature.

After the standing valve assembly 42, carrying the valve means .21 and the pressure responsive means 28, has been run in in the foregoing manner and is disposed in its operating position, the fluid-operated, free pump |5 is then moved hydraulically, or otherwise, through the power tubing I2 into its operating position wherein it is seated on the pump seat IB provided by the standing valve assembly, any fluid in the power tubing below the pump being displaced upwardly through the production tubing I8 because of the fact that the standing valve 48 prevents reverse flow through the passage means 23 leading to the reservoir 22.

Operating iluid under pressure from a suitable source from the surface may then be delivered to the fluid-operated pump I5 through the power tubing I2 to operate the pump, whereupon the pump draws fluid from the reservoir 22 through the passage means 23 and discharges n the pressure responsive means 28 is set, the bellows |24 is compressed to such an extent that the spring I I8 closes the valve |03 to prevent any flow of well iiuid from the well into the reservoir 22 until such time as the level in the reservoir is reduced to the predetermined value. Thereafter, the pressure responsive means 28 maintains the valve |03 in such a position that the level in the reservoir is maintained at the desired value.

Preferably, the pressure responsive means 28 cooperates with the valve means 21 to maintain the level in the reservoir 22 a substantial distance below the discharge means 26 so that the well fluid entering the reservoir through the passage means discharges into gas, rather than liquid. The well fluid entering the reservoir is discharged against the casing 9 by the discharge means 28 in the manner hereinbefore indicated so as to spread the well fluid over the casing in a thin film which drains downwardly in to the body of liquid in the reservoir. This action results in separation of a substantial quantity of the gas in the well iiuid from the liquid components thereof so that the gas does not interfere with the operation of the pump |5.-- `As previously discussed, the discharge means 26 preferably discharges the well uid against the casing 9 tangentially to attain essentially a cyclone separator effect, thereby insuring better gas separation. The distance .that the liquid level is maintained below the discharge means 26 by the pressure responsive means 28 and the valve means 27 depends upon the degree ofseparation desired, which distance probably should not be less than approximately ten feet and might be as much as feet. Y

It will be understood that the gas pressure in the reservoir 22 above the liquid level'therein is desirably maintained at substantially atmospheric pressure by drawing gas off from the casing 3 through the pipe 29. Thus, when the well iluid discharges into the reservoir 22, the pressure thereon has been suddenly reduced at the valve |83 and the gas in solution in the liquid has been liberated therefrom with turbulence so that the amount of gas in the oil is greatly decreased and corresponds approximately to equilibrium conditions at the temperature and pressure in the reservoir.

It is desirable that the liquid level in the reservoir 22 be maintained a substantial distance above the inlet 24 of the pump I5 so that the fluid entering the pump is subjected to a substantial pressure. Consequently, the fluid entering the pump is less than saturated and this tends to prevent or at least minimize liberation of gas in the pump, thereby maintaining a high pumping eniciency.

In order to remove the pump I5 from the well, it is merely necessary to reverse the flow of operating iiuid through the system, i. e., to directr the flow of operating fluid downwardly throughV the production tubing I3, instead of the power tubing I2, by means of a suitable valve mechanism (not shown) on the surface. The operating fluid directed downwardly through vthe production tubing I 3 in this manner enters the power tubing I2 below the pump I5 and acts on an annular area |35 at the lower'end of the pump to unseat the pump, the operating fluidpressure thereafter acting on the entire cross-sectional area of the pump to move the pump upwardly through the power tubing I2 to the surface.v As will be apparent, the standing valve 48 closes under such conditions to prevent reverse ilow through the passage means 23 leading from the reservoir 22.

After the pump I5 has been removed, if it is desired to remove the standing'valve assembly 42 from the well for any reason, such as to service or repair the standing valve 48, the valve means 21, or the pressure responsive means 23,4 this may be accomplished readily by lowering a suitable tool into the power tubing I2 on the end of a wire line to engage the standing valve assembly. Thereafter, the standing valve 'assembly may be pulled upwardly through the power tubing I2 to the surface. i

Referring to Fig. 4., the housing 20 of the pump inlet apparatus I4 is provided with a lay-pass passage |48 which communicates at its lower end with the well through the casing packer 2| and which communicates at its upper end with an annular space |4| between the bore 4| and the standing valve assembly d2. The standing valve assembly is provided with a frangible Vdrain plug |42 which is adapted to connect theannular space |*4I to the interior of the'jtube 45. The drain plug |42, which is Icustomarily termed l1 a knockout plug, is hollow sothat it connects the `space l4l and the tube 45 when the inner endA thereof is broken oi, asby dropping a knockout bar through the power tubing l2. The pu;- pose of this arrangement is to-provide a. way of draining the tubings l2 and I3 to balance the pressure on the standing valve assembly so that it may be readily pulled with a wire line.

Although I have disclosed an exemplary embodiment of my invention for purposes of illustration, it will be understood that I do not intendl to-be limited speciiically thereto since variouschangesmodications and substitutions may be incorporated in such embodiment without departing from the spirit of the invention.

I- claimY as-my invention:

l.` In a device of the character described, the combination of: a reservoir for well iluid from a well adapted to produce liquid. and gas; passage meansfhavingan upper end for connecting said reservoir to the well in fluid communication therewith so as to convey well huid from the well to-said reservoir; valve means in said passage means and including a valve for regulating flow of well iuid: throughA said passage means, said valve having oppositely facingsubstantially equal. areas; a passage connecting said areas to sourcesof substantially equal fluid pressures so as to substantially hydraulically balance said valve; and means responsive to variations in the'amount of liquid in` said reservoir and operatively connected to-said valve means for maintaining the liquid level in said reservoir below the upper end ot said. passage means.

2. Inv adevice of the character described, the combination of a reservoir for well' iluid from a Well adapted to produce liquid and gas; passage means having an upper end for connecting said reservoir tothe well in iluid communication ltherewithso as toconvey Well fluid from the well to saidreservoir; valve means in said passage means and including a reciprocable valve having ends of. substantially equal areas for regulating ow of well uid through said passage means; meansfor exposing the ends of said Valve to substantially equal uid pressures so as to substantially hydraulically balance said valve; and means. responsive to variations in the pressure of the well' fluid in said reservoir. and operatively connected to said. valve means for maintaining the liquid level in said reservoir below the upper end of saidv passage means.

3. In a device of the characterv described, the combination of: a reservoirA for well fluid from a well; passage means for connecting said reservoir toV the well in fluid` communication therewith so as to convey wellv fluid from the well to said reservoir; valve means in said passage means for regulating flow of well fluid through said passage means; meansl including a bellows for actuating/said valve means, saidA bellows containing ai liquidA and a gas; and means for exposing the exteriorA of said bellows to the pressure of the well uid in said reservoir;

4. In a deviceV of the character described, the combination of a reservoir for well fluid from a Well;y passage., means-for connecting said reservoir to the Wellin fluid-communicationr therewith so as to convey well fluid from the well to said reservoir; valve meansinsaid passage means for regulating. flow of well fluid through said passage. means; means including a bellows for actuating said valve means, said bellows containing avolume of liquid equal tol at leastone-half the. volume thereof, the balance of said bellows 12 containing agas and means for exposingv the exterior of said bellows to the pressure of the well fluid in said reservoir.

5. In an apparatus for delivering well iiuid to the inlet of a well pump, the combination of: a reservoir for well fluid from a well; passage means for connecting said reservoir to the well in fluid communication therewith so as to convey well fluid from the well to said reservoir; a first seat; pump inlet means adapted to seat on said iirst seat and providing a second seat for the inlet of the well pump; another passage means connecting said reservoir to said second seat so as to convey well fluid from said reservoir to the inlet of the well pump; and means carriedV by said pump inlet means for regulating flow of well fluid through said passage means into said reservoir in accordance with variations in the amount of well fluid in said reservoir.

6. In an apparatus for delivering well fluid to the inlet of a well pump, the combination of: a reservoir for well uid from a well; a chamber providing a first seat; first passage means communicating intermediate its ends with said chamber for connecting said reservoir in uid communication with the well so as to convey well Huid from the well to said reservoir; pump inlet means insertable into said chamber and seatable on said first seat, said pump inlet means providing a second seat for a well pump; second passage means communicating at one end with said reservoir and adapted to communicate at its other end with the inlet of a well pump seated on said second seat. for conveying well fluid from said reservoir to the inlet of the well pump; valve means carried by said pump inlet means for regulating flow of wellfluid through said rst passage means into said reservoir; and pressure responsive means carried by said pump-inlet means and' actuable in response to variations in the amount of well fluidin said reservoir for actuating said valve means.

'7; In an apparatus for delivering well uid to the inlet of a well pump, the combination of:` a reservoir for well fluid from a well; a chamber providing a first seat; first passage means communicating intermediate its ends with said chamber for connecting said reservoir in uid communication with the well so as to convey well fluid from the well to said reservoir; pumpl inlet means insertable into said chamber and seatable on said first seat, said pump inlet means providing a second seat for a. well pump; second passage means communicating at. one end with said reservoir and adapted to communicate at its other end with the inlet of a well pump seated on said second seat for conveying well fluid from said reservoir to the inlet of the well pump, said second passage means traversing said pump nlet means; valve means carried by said pump inlet means for regulating flow of well iiuid through said rst passage means into said reservoir; and pressure responsive means carried by said pump inlet means and exposed tov the pressure of well fluid owing through said second passagemeans for actuating said valve means in response to variations in the pressure of well uid ilowing through saidv second passage'means'.

8. In an apparatus for delivering well fluid to the inlet ofv a well pump, the combination of: a reservoir-for well fluid from a well; a chamber providing a rst seat; first passa-ge means communicating intermediate its ends with said chamber for connecting said reservoir in uid ccmfacvs, 192

municationwith thewell so as to convey well fluid from the well to said reservoir; pump inlet means insertable into said chamber and seatable on said rst seat, said pump inlet means providing a second seat for a well pump; second passage means communicating at one end with said reservoir and adapted to communicate at its other end with the inlet of a well pump seated on said secondseat for conveying well iiuid from said reservoir to the inlet of the well pump, said second passage means traversing said pump inlet means; valve means carried by said pump inlet means for regulating flow of well fluid through said first passage means into said reservoir; pressure responsive means carried by said pump inlet means and exposed to the pressure of well fluid ofwing through said second passage means for actuating said valve means in response to variations in the pressure of well duid iiowing through said second passage means; and check valve means carried by said pump inlet means for preventing flow through said second passage means into said reservoir.

9. In an apparatus for delivering well uid to the inlet of a well pump, the combination of: a reservoir for well iluid from a well; a chamber providing a first seat; rst passage means communicating intermediate its ends with said chamber for connecting said reservoir in fluid communication with the well so as to convey well fluid from the well to said reservoir; pump inlet means insertable into said chamber and seatable on said iirst seat, said pump inlet means providing a second seat for a well pump; second passage means communicating at one end with said reservoir and adapted to communicate at its other end with the inlet of a well pump seated on said second seat for conveying well iiuiol from said reservoir to the inlet of the well pump, said second passage means traversing said pump inlet means; valve means carried by said pump inlet means for regulating flow of lwell fluid through said rst passage means into said reservoir; pressure responsive means carried by said pump inlet means and exposed to the pressure of well iiuid owing through said second passage means for actuating said valve means in response to variations in the pressure of well fluid flowing thro-ugh said second passage means; check valve means carried by said pump inlet means for preventing flow through said second passage means into said reservoir; a pair of tubings extending downwardly into the well and secured at their lower ends relative to said rst seat with one of said tubings substantially aligned with said first seat, said pump inlet means being movable through said one tubing to seat `on said rst seat; a fluidoperated well pump movable through said one tubing to seat on said second seat, said well pump having an inlet communicating with said other end of said second passage means when said well pump is seated on said second seat, and having an outlet; and third passage means for connecting said outlet to the other of said tubings when said well pump is seated on said second seat.

10. In a pump inlet device, the combination of a reservoir; a pump inlet body having first and second passages therethrough, said first passage having an outlet end connected to said reservoir and said second passage having an inlet end connected to said reservoir, said second passage having an upper, outlet end and having at its outlet end a seat for a lower, inlet end of a pump; valve means carried by said body for regulating flow through said rst passage; said pressure responsive means carried by said body and exposed to iluid pressure in said second passage for actuating said valve means.

11. In a pump inlet device, the combination of: a pump inlet body having iirst and second passages therethrough, said second passage having an upper, outlet end and having at its outlet end a seat for a lower, inlet end of a pump; reservoir means for connecting said passages in series; valve means carried by said body for regulating iiow through said rst passage; and pressure responsive means carried by said body and exposed to iiuid pressure in said second passage for actuating said valve means, said pressure responsive means including a bellows oontaining a liquid and a gas and having its exterior exposed to fluid pressure in said second passage.

12. In a pump inlet device, the combination of a pump inlet body having rst and second passages therethrough, said second passage having an upper, outlet end and having at its outlet end a seat for a lower, inlet end of a pump; valve means carried by said body for regulating flow through said iirst passage; pressure responsive means carried by said body and exposed to iiuid pressure in said second passage for actuating said valve means; and check valve means carried by said body for preventing flow in one direction through said second passage.

13. In a pump inlet device, the combination of a pump inlet body having first and second passages therethrough connected by a reservoir; valve means carried by said body for regulating flow through said first passage; pressure responsive means carried by said body and exposed to fluid pressure in said second passage for actuating said valve means; and a pump seat encompassing one end of said second passage.

14. A pump inlet device, comprising: rst and second passages; reservoir means for connecting said passages in series; valve means for regulating flow through said first passage; and pressure responsive means for actuating said valve means, said pressure responsive means including a bellows containing a liquid and a gas and having its exterior exposed to fluid pressure in said second passage.

15. In a fluid-operated well pumping system, the combination of power and production tubings set in a well; a reservoir enclosing the lower ends of said tubings; passage means communicating at one end with the well and at its other end with said reservoir for conveying well fluid from the well to said reservoir, said passage means including a third tubing in said reservoir beside said power and production tubings; a fluid-operated pump actuable by an operating fluid under pressure delivered thereto through said power tubing, said pump having an inlet communicating with said reservoir and an outlet communicating with said production tubing; and means for regulating flow of well iuid through said passage means into said reservoir in accordance with variations in the amount of well uid in said reservoir.

16. In a device of the character described, the combination of: a reservoir for well iluid from a Well; and passage means for connecting said reservoir in fluid communication with the well to convey well fluid from the well to said reservoir, said passage means communicating with said reservoir in a zone above the bottom of said reservoir through discharge openings in said passage means, said discharge openings being disposed adjacent and Abeing directed towardawall .of said reservoir and the axes of vsaid discharge openings making acute angles; with said wall so that the Well fluid impinges substantially tangentially on said Wall.

17. A pump inlet device according to claim 12 including means for biasing said check valve kmeans open.

18. A pump inlet device according to claim 12 .including magnetic means for biasing said check valve means open.

19. A pump inlet device according to claim 8 including means for biasing said check valve means open.

References Cited inthe le fof this patent Number UNITED STATES PATENTS Name Date Vail et al Apr. 11, 1893 Action `May 16, 1893 Birkeny Feb. 2.7, 1894 Nashlund Aug. 22, 1916 Coberly Nov. 14, 1939 Coberly Jan. 11, 1944 Crtes May 2, 1944 Walton Aug. 10, 1948 OLeary Nov. 29, 1949 Stages etal May 20, v1952 

